Tom Gjelten

To Donald Trump, one of President Obama's major failings was his refusal to identify "radical Islam" specifically as America's top adversary.

"Anyone who cannot name our enemy is not fit to lead this country," Trump told a crowd in Ohio in August. "Anyone who cannot condemn the hatred, oppression and violence of radical Islam lacks the moral clarity to serve as our president."

Five centuries ago, Christians in Europe who hoped to go to heaven knew they might first have to spend a few thousand years in a fiery purgatory, where they would be purified of their outstanding sins.

It was not a pleasant thought, but the Catholic Church offered some hope: A cash offering to the local priest could buy an "indulgence" certificate, entitling the believer to a shorter purgatory sentence.

For more than 30 years, conservative evangelical Christians have been tied to the Republican Party. While the pattern seems to be holding this year, with most conservative white Christians supporting Donald Trump, some evangelical leaders are now questioning the logic behind the political alliance.

Freedom of religion is enshrined in the U.S. Constitution, but to Dan Meyer, a North Carolina businessman, that does not mean the Founding Fathers were not inspired by God.

"Many documents demonstrate that they really received divine guidance in putting together that constitution," he says. "It's not the Bible. It is a man-made document. But most of the writers of that document acknowledged that God gave them guidance and wisdom in putting that document together."

Fifteen years after the attacks of Sept. 11, Americans have grown aware not only of the danger of terrorism but also of the reality that their nation is far less white, Christian and European than it used to be.

"Culturally, we're a country of Bollywood and bhangra and tai chi and yoga and salsa and burritos and halal and kosher," says Diana Eck, professor of comparative religion at Harvard University and author of A New Religious America.

Hundreds of Catholics have been declared saints in recent decades, but few with the acclaim accorded Mother Teresa, set to be canonized by Pope Francis on Sunday, largely in recognition of her service to the poor in India.

"When I was coming of age, she was the living saint," says the Most Rev. Robert Barron, the auxiliary bishop of the Archdiocese of Los Angeles. "If you were saying, 'Who is someone today that would really embody the Christian life?' you would turn to Mother Teresa of Calcutta."

Churchgoing Americans say their preachers often speak out on hot social and political issues and occasionally back or oppose particular candidates in defiance of U.S. law prohibiting such endorsements.

(Editor's note: Both major presidential candidates this year are Protestants. Both of their running mates were raised as Catholics. Beyond that, their faith profiles are very different. We dug into the faiths of the Republican candidates below and of the Democratic ticket here.)

(Editor's note: Both major presidential candidates this year are Protestants. Both of their running mates were raised as Catholics. Beyond that, their faith profiles are very different. We dug into the faiths of the Democratic candidates below and of the Republican ticket here.)

The Jews who immigrated to America in the early 20th century brought with them their history as a persecuted people. Many were fleeing pogroms and anti-Semitic attacks in Europe, and those experiences bonded them to other groups that also faced discrimination.

America's culture war, waged in recent years over gender roles, sexuality and the definition of marriage, is increasingly being fought inside evangelical Christian circles. On one side are the Christians determined to resist trends in secular society that appear to conflict with biblical teaching. On the other side are the evangelicals willing to live with those trends.

For Albert Mohler, president of the Southern Baptist Theological Seminary in Louisville, Ky., the key question is "whether or not there is a binding morality to which everyone is accountable."

The global refugee crisis, political strife and economic dislocation all contributed to a worldwide deterioration of religious freedom in 2015 and an increase in "societal intolerance," according to the U.S. Commission on International Religious Freedom.

"At best, in most of the countries we cover, religious freedom conditions have failed to improve," says Princeton professor Robert George, the USCIRF chairman. "At worst, they've spiraled downward."

Editor's note: Radovan Karadzic was one of the dominant figures of the Bosnian war, serving as president of the "Serb Republic" in Bosnia from 1992 to 1995. The International Criminal Tribunal in The Hague on Thursday found him guilty of multiple crimes, including the slaughter of about 8,000 Muslim men and boys in the town of Srebrenica. NPR's Tom Gjelten covered the war in Bosnia, and Karadzic, for years.

Given all that has happened in the last 20 years, many people will not recall the war in Bosnia. Remind us what happened.

For Muslim-Americans, there was a world before Sept. 11 and the wars in Afghanistan and Iraq, and one after. Now, their community faces the dual threats of extremism and growing atheism.

Young Muslim-Americans are angry and frustrated, but not necessarily for the reasons you might think. While bound by their religion and their community, they have opinions as diverse as their backgrounds.

Antonin Scalia was just one of six Roman Catholic justices on the Supreme Court, but in his devotion to the faith he was second to none. Neighbors saw him and his wife, Maureen, worshipping frequently at St. Catherine of Siena in Great Falls, Va., a church Scalia was said to favor because it was one of the few Catholic parishes in the Washington, D.C., area that still offered a Latin mass.

In 1054, Pope Leo IX excommunicated the patriarch of Constantinople, an occasion that would go down in history as the beginning of the "Great Schism" between the Roman Catholic and Eastern Orthodox churches.

With the 1,000-year anniversary of the split just a few short decades away, Pope Francis and Patriarch Kirill of Moscow and All Russia will meet Friday in Havana as they attempt to bury the hatchet.

The rise of ISIS and other Muslim extremist groups in the Middle East, Africa and South Asia has brought horrific persecution of non-Muslims — Christians, Jews and other religious minorities. Now, a group of Islamic scholars, Muslim leaders and government ministers from Muslim-majority countries has promised to work together to protect those minorities, saying Islam forbids religious persecution.

Christian conservatives who are battling for the right to promote their faith in public or official settings see themselves locked in an epic contest with a rival religion. But that rival isn't Islam. It's secularism.